Vehicle air suspension assembly

ABSTRACT

A vehicle air suspension assembly comprising a first beam, a first air spring mounted between the forward end of the first beam and the vehicle chassis, and a second air spring mounted between the rearward end of the first beam and the vehicle chassis. The assembly also includes a second beam, means for pivotally supporting the forward end of the second beam from the vehicle chassis near the first air spring, and means for pivotally supporting the rearward end of the second beam near the rearward end of the first beam. The vehicle axle is mounted to the first beam, whereby the first beam, and hence the vehicle axle, totally support the vehicle chassis on the air springs, the second beam acting to push and pull the vehicle axle and stabilize the assembly. Inherent in the assembly design are means for retracting the vehicle axle and means for allowing for oscillation of the axle as caused by one end of the axle moving up or down relative to the other under various load and road conditions.

United States Patent [191 Raidel [4 1 Feb. 26, 1974 [22] Filed:

'[21 Appl. No.: 270,253

[ 1 VEHICLE AIR SUSPENSION ASSEMBLY [76] lnventor: John E. Raidel, Rt.9, Box 400-M,

' Springfield, Mo. 65804 Jul 10,1972

[52] US. Cl. 280/124 F, 267/ R [51] Int. Cl. 860g 11/28 [58] Field ofSearch ..'267/15 R, 15 A; 280/124 [56] References Cited UNITED STATESPATENTS 2,903,256 9/1959 Weiss 267/15 A Primary ExaminerPhilip GoodmanAttor'ney, Agent,dr FirinRogers,'Ezell & Eilers s71 ABSTRACT A vehicleair suspension assembly comprising a first beam, a first air springmounted between the forward end of the first beam and the vehiclechassis, and a I second air spring mounted between the rearward end ofthe first beamand the vehicle chassis. The assembly also includes asecond beam, means for pivotally supporting the forward end of thesecond beam from the vehicle chassis near the first air spring, andmeans for pivotally supporting the rearward end of the second beam nearthe rearward end of the first beam. The vehicle axle is mounted to thefirst beam, whereby the first beam, and hence the vehicle axle, totallysupport the vehicle chassis on the air springs, thefsecond beam actingto push and pull the vehicle axle and stabilize the assembly.

Inherent in the assembly design are means for retracting the vehicleaxle and means for allowing for oscillation of the axle as caused by oneendof the axle moving up or down relative to the other under variousload and road conditions.

Claims, 10 Drawing Figures PATENTEDfEBZB QM SHEET 1 BF 3 SUMMARY OF THEINVENTION This invention relates to a vehicle suspension assembly, andparticularly to an airsuspension assembly having axle retracting meansand which combines an extremely comfortable ride with exceptionalstability.

The suspension assembly of this invention includes a hanger assemblydepending from the side of the vehicle chassis. The forward end of atorque beam is pivotally mounted about a bushing assembly mounted in thehanger assembly, the torque beam extending, rearwardly with itsrearward-end pivotally mounted about another bushing assembly mounted inthe rearward end of a bolster beam. One air spring is mounted betweenthe rearward end of the bolster beam and the vehicle chassis, andanother air spring is mounted between the forward end of the bolsterbeam and the hanger assembly so that the bolsterbeam is effectivelysupported at chassis issupported on the-axle with the air springsbearing the total load for exceptional comfort and the FIG. 3 is a leftend elevation view taken along the line 3-3 of FIG. 2 with the doubleconvolution air spring omitted;

FIG. 4 is a right end elevation view taken along the line 4-4 of FIG. 2;

FIG. 5 is an enlarged view in section taken along the I line 5-5 of FIG.2; v

FIG. 6 is a view in section taken along the line 6-6 of FIG. 2;

FIG. 7 is a side elevation view similar to FIG. 2 but showing theassembly in its downwardly extended position;

- each of its ends to the chassis totally by air springs. One

torque beam acting to push andpull the vehicle axle I and stabilize theassembly. At the same time the design of this invention permitsoscillation of the axle about the longitudinal axis of the torque beamwhich occurs when one end of the axle moves up or down with rewardlyextended position, thus relieving the strain on the shock absorbercustomarily used for this purpose.

Inherent in its design is still another primary feature of thisinvention which provides means for lifting the axle to a retractedposition where the vehicle has more than one axle. This isaccomplished'by depressurizing the rear air spring and maintainingpressure in the forward air spring causing the rearward end of thebolster beam, and hence the axle, to lift under the resultant momentforces about the hanger bushing assembly. Hence, not only does thisinvention provide a complete air ride suspension but also providesinherent in its design means for retracting the axle.

These and other features of the invention are apparent from the drawingsand the detailed description to follow.

DESCRIPTION or THE DRAWINGS FIG. 1 is a top plan view of an airsuspension assem bly of this invention;

' FIG. 2 is a side elevation view of the suspension assembly of FIG. 1;r

FIG. 8 is a side elevation view similar to FIG. 2 but showing theassembly in its retracted position;

FIG. 9 is an enlarged view in section taken along the line 9-9 of FIG.2; and

FIG. 10 is a view similar to FIG. 9 to illustrate the 0scillatingfeature of this invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT to both assemblies. It isfurther to be understood that more than one suspension assembly may bemounted on each side of the chassis such as where multiple axles areused. Because each of the assemblies of this invention are identical,only a single left side assembly will be described, so that in viewingFIG. 2, forward motion of the vehicle is to the left.

r The principal components of the suspension assembly 20 comprise ahanger assembly 28 suspended from the side member 22, a torque beam 30having one end connected to the hanger assembly and its other endconnected to one end of a bolster beam 32. Between the same end of thebolster beam 32 and the chassis member 22 is an air spring 34, andbetween the other end of the bolster beam 32 and a bracketextension 36of the hanger assembly 28is a second air spring 40. The axle 25 isconnected to the bolster beam 32 and a shock absorber 42 is connectedbetween the bolster beam 32 and the hanger assembly 28.

The hanger assembly 28 comprises a pair of extruded hanger rails 46 and47, the upper ends of which are welded to a hanger bracket 48. Thehanger bracket 48 is fastened by a plurality of bolts 49 to the chassisside member 22 and is suitably reinforced with gusset plates 50.

Each of the hanger rails 46 and 47 is formed with a face plate 55 withvertical webs 56-, 57, 58 and 59, and has a central vertical slot-60. Areinforcing plate 61 is welded across the top of the slot 60 of each ofthe rails 46 and 47. One end 62 of a brace member 63 is welded to theface plate 55 between the webs 58 and 59 of the hanger rail 47, with theother end of the brace member 63 welded to the corresponding hanger railof the right air suspension assembly (not shown) at the opposite side ofthe vehicle.

A bushing assembly 68 is mounted between the hanger rails 46 and 47. Thebushing assembly 68, as

best shown in FIG. 5, comprises a bolt 69 extending through a hole 70ina plate 71 positioned between the webs 57 and 58 and bearing againstthe face plate 55 of the rail 46. The shank of the bolt 69 furtherextends through a hole 73 in a narrower plate 74 which is welded to theinner face of the plate 71 and rides within the slot 60 of the hangerrail 46, and through a hole 76 in another narrow plate 77 that rideswithin the slot 60 of the hanger rail 47, and which is welded to theinner face of a plate 78. The plate 78 is like the plate 71 but ispositioned between the webs 57 and 58, and bears against the face plate55, of the rail 47. The shank of the bolt 69 extends through a hole 80in the plate 78. A nut 81 is used to tighten the bushing assembly 68 inplace.

The bolt 69 has a cam member 83 which projects to one side and acts asan eccentric. An arrow 84 (FIG. 2) is drawn or stamped on the face ofthe head of the bolt 69 and points to the central high rise of the cameccentric 83. A metal sleeve 85 surrounds the shank and cam eccentric 83of the bolt 69, and a rubber bushing 87 surrounds the sleeve 85. Thepurpose of the eccentric bolt is to provide means for aligning the axlein the manner described in U. S. Pat. No. 3,510,149. Once the verticallocation of the bushing assembly 68 has been selected within the hangerassembly 28 as de- An air spring mounting plate 130 is welded to the topflanges of the beam 32 at its rearward end. The air spring 34 is ofconventional design, having an air spring body 134 above a base 135, andan internal bumper 135' of rubber or other suitable material. The base135 is mounted such as by bolts 136 to the air spring mounting plate130. An upper mounting bracket 138, which is actually an extension ofthe hanger mounting bracket- 48, is fastened by bolts 139 to the sidemember 22 of the vehicle chassis. The bracket 138 includes a horiscribedin U. S. Pat. No. 3,510,149, the plates 71 and 78 are welded in place; I

The torque beam is tubular and terminates at its forward end in a sleevemember 90 and at its rearward end in a sleeve member 91. The sleevemember 90 surrounds the rubber bushing 87 of the bushing assembly 68 forpivotal movement thereabout. Metallic washers 93 and 94 surround thesleeve 85 and are located at oppositev ends of the bushing 87 and thesleeve member 90 to provide a relatively tight fit of the sleeve 90'between the hanger rails 46 and 47, thus prohibiting any appreciablemovement of the sleeve 90 back and forth between the hanger rails 46 and47 and prohibiting any appreciable rotation of the torque beam 30 aboutits longitudinal axis to insure maintenance of proper wheel tracking andalignment as the vehicle rounds corners i the bolt 69 andnut 81, plates113 and 114 like the plates 71 and 78, which plates 113 and 114 arewelded to the outer surfaces of the members 105 and 106, and have holes115 and 116 through which the bolt extends, and a cam member117, ametallic sleeve 118 zontal plate 141 and reinforcing gussets 142. Theupper side of the air spring body 134 is fastened to the plate 141 bynut and bolt assemblies 143.

The .forward end of the bolster beam 32 extends somewhat forward of thehanger assembly 28 and is inclined so that the end tends to facegenerally upward. The inclined end is covered with amounting plate 150which is mounted in place such as by welding. The bracket extension 36of the hanger assembly 28 has reinforcing gussets 151 to which ismounted at their lower surfaces a plate 152. As best shown'in FIG. 2,the plate 152 is not horizontal but is inclined slightly so as to begenerally parallel to the plate 150 at the forward end of the bolsterbeam 32. The air spring 40, of any suitable type such as the doubleconvolution type shown, is mounted between the plates 150 and 152 suchas by bolts 155, and includes an internal bumper 156 of rubber or othersuitable material.

The axle 25 is mounted to the bolster beam 32 by means of an axlemounting bracket 160 that straddles the torque beam 30 to allow verticalmovement of a portion of the torque beam the'rebetween. The axle 162 and163 welded to the inside surfaces of, and extending upwardly from, themembers 105 and 106, re-

and a rubber bushing 119 likethe cam member 83, me-

tallic sleeve and rubber bushing 87 of thebushing assembly 68. Themembers and 106 also have holes and 121 through which the bolt 110extends.

The rearward sleeve 91 of the torque beam 30 surrounds the rubberbushing 119 of the bushing assembly 108 for pivotal movement thereaboutfor purposes to be hereinafter described in more detail.

One important difference between the bushing assemblies 68 and 108 isthat there are no washers in the bushing assembly 108 such as thewashers 93 and 94 in spectively, of the bolster beam 32. Each of theplates 162 and 163 has a semicircular. shaped recess 165 ofapproximately the same radius as the axle 25. ,T he axle 25 is securedin the semi-circular shaped recesses 165 such as by welding. To add-siderigidity to the axle mount 160, on each side of the axle there arereinforcing plates 167, 168, and 169 which are shaped generally as shownin FIG. 6. The plates 167 and 169 are mounted outside the plates 162 and163 and are secured at their lower ends to the plates 162 and 163 andthe tops of the members 105 and 106 of the bolster beam 32, and at theirtops to the axle such as by welding. The middle plate 168 is mounted atits lower end to the plates 162 and. 163 and at its top to the axle alsoaxle bracket provides a very rigid and secure supbeam 32 to accommodatelower axle port for the axle on the bolster beam 32, yet permitsmovement of the torque beam therein.

While the axle has been described as mounted over the beam 32, it couldobviously be mounted under the height requirements.

- the bushing assemblies 68 and 108.

Also mounted between the vertical parallel plates 162 and 163 is a stopplate 170 located just forward of the axle 25 and oriented generallyparallel to the longitudinal axis of the torque beam 30. The plate 170is positioned directly on top of or slightly above the torque beam 30.The purposes of the stop plate 170 are to prevent any tendency for theaxle- 25 to rotate when the brakes are applied with the vehicle movingforward, and to reinforce the axle bracket 160. It also cooperates withthe torque beam 30 and bumper 156 to support the axle in the downwardlyextended position as will be described. Another reinforcing plate 171 ismountedbetween the vertical plates 162 and 163 just rearward of the axle25 above the torque beam 30.

As best Seen in FIGS. 2 and 3 the shock absorber 42,

of a type commonly known in the art, is connected by nut and boltassemblies 175 between the hanger assembly 28 and the bolster beam 32,with the top end of the shock absorber 42 connected to a flangeextension 177 of the hanger assembly 28 and its bottom end connected tothe inner-side of the member 106 of the bolster beam 32 at a locationgenerally beneath the axle 25.

Operation The functions of the suspension assemblies are to resilientlysupport varying total loads carried by the vehicle body above thevehicle chassis 24, and to provide an extremely comfortable yetexceptionally stable air spring suspension, as well as a means forretracting selected ones of the axles of a multiple axle vehicle as thevehicle load conditions permit, thus saving unnecessary wear and tear ontires and-the like. 1

FIGS. 2, 7, and.8 illustratethree conditions of the suspension assembly20, FIG. 2 illustrating the condition under normal load, FIG. 7illustrating the extended position such as where the wheel falls into ahole, and FIG. 8 illustrating the retracted position with'the wheel offthe ground such as is used with multiple axle vehicles under light loadconditions.

At theoutset it should be noted that the entire load is carried'on thetwo air springs 34 and 40 to provide a completely air spring support ofthe chassis on the axle with greatly increased comfort. In thisdescribed embodiment the spring 34, being the larger of the two, supportapproximately two-thirds of the load with the axle mounted closer to itthan the spring 40. In normal operation, the condition of FIG. 2, bothsprings 34 and are kept under positive air pressure. When the axle 25moves upward with respect to the chassis 22 such as where a wheel hits abump in the road, both air springs 34 and 40 compress an amountdepending on the load. As the axle 25 moves downward, such as wouldoccur if the wheel drops into a hole, both of the air springs 34 and 40extend. It should be noted that as the axle 25 moves up and down undervarying load conditions, the bolster beam 32 likewise moves up and downwith the rearward end of the torque beam 30 which is attached to thebolster beam 32 bythe bushing assembly 108. Hence, this up and downmovement causes pivotal movement of the torque beam 30 about It isanother primary feature of this invention that the bushing assemblies 68and'108 and the torque beam 30 stabilize the suspension assembly,preventing transverse, forward and rearward movement of the axle 25, yetpermitting vertical movement of either or both ends of the axle. Aspreviously stated, the bushing assembly 68 has end washers 93 and 94that prevent the forward end of the torque beam 30 from movingtransversely between the hanger rails 46 and 47. These same washers 93and 94 also prevent rotation of the torque beam 30-about itslongitudinal axes. However, the bushing 108 does not have washers suchas the washers 93 and 94 thus leaving the spaces 123 and 124 between theends of the sleeve 91 and the inner surfaces of the members and 106.This permits some oscillating movement of the axle 25 about thelongitudinal axis of the torque beam 30, and hence the bushing-assembly108 within the sleeve end 91, due to the inherent flexibility of therubber bushing 1 19. For example, if the left end of the axle 25 movesupward with respect to its right end and the chassis 22, the axle 25,its support 160, the bolster beam 32, and the bushing assembly 108 wouldtake the general position shown in FIG. 10, it being remembered that thesleeve end 91 of the torque beam 30 remains generally fixed since thetorque beam 30 is prevented from rotating by the washers 93 and 94 inthe bushing assembly 68.

' The stop 170 is another primary feature of this invention. When thebrakes of the vehicle are applied, the great torque forces onthe axle 25tend to rotate the axle 25 in a counterclockwise direction as viewed inFIG. 2. This produces a very unstable conditionknown as brake-hopping.However, with this invention as the brakes are applied, the stopplate170 bears down on top of the torque beam 30, preventing any tendency forthe axle 25 to rotate andthus preventing brake-hop.

FIG. 7 illustrates the fully extended position of the suspensionassembly 20 as would occur if the wheel were to fall into a deep hole orif the chassis were to move suddenly upward to a point where the wheelleaves the ground. In this condition the stop plate 170 bears downwardlyon the beam 30 and the air spring 34 is fully extended with the positivepressure in the air spring 40 overcome by the weight of the axle, wheel,etc., such that the air spring34 becomes fully compressed. With the airspring 34 fully compressed, the torque beam 30 and the internal bumper156 of the air spring 40 at the forward end of the bolster beam 32support the vehicle axle 25. This is another primary feature of thisinvention, for; without the torque beam 30the shock absorber 42 wouldhave to act as the lower limit support for the axle 25 which would causeconsiderable strain on the shock absorber and greatly reduce its life. 4

FIG. 8 illustrates the retracted position of the axle 25 which is usedto lift the axle and its wheels off the ground. To create thiscondition, the air spring 34 is depressurized and the air spring 40 ismaintained under pressure or increased pressure causing the forward endof the bolster beam 32 to drop and the rearward end of the bolster beam32 to raise as the torque beam 30 pivots about the bushing assemblies 68and 108 until the bumper hits the top of the air spring 34. The bumpers135 and 156 each protects the other air spring from overextension.Raising of the rearward end of the bolster beam 32 raises the axle25. Tolower the axle beam, first spring means between the forward end of thefirst beam and the vehicle chassis, the first spring means being mountedat an inclined angle such that extension thereof tends to move theforward end of the first beam in a downward and rearward direction,second spring means between the rearward end of the first beam and thevehicle chassis, a second beam, means associated with the chassis forpivotally supporting the forward end of the second beam from the vehiclechassis, means associated with the first beam for pivotally supportingthe rearward end of the second beam from the first beam, and means formounting the vehicle axle to the first beam.

2. The suspension assembly of claim 1 wherein the rearward end of thesecond beam is pivotally supported near the rearward end of the firstbeam, and the vehicle axle is mounted forward of this pivotallysupporting means. 7 r

3. The suspension assembly of claim 1 wherein the first and secondspring means are air springs.

4. The suspension assembly of claim 3 including a hanger assemblydepending from the vehicle chassis, and means for pivotally mounting theforward end of the second beam to the hanger assembly.v

5. The suspensionassembly of claim 1 wherein the pivotally supportingmeans include bushing assemblies having resilient bushing means therein.

6. The suspension assembly of claim 1 including oscillation dampeningmeans mounted between the first beam and thevehicle chassis.

7. The vehicle suspension assembly of claim 1 including a stop meansassociated with axle movement and which bears downwardly on the secondbeam to prevent rotation of the axle when the brakes are applied. 8. Thevehicle suspension assembly of claim 1 wherein the pivotally supportingmeans includes resilient bushing means at least one of which: permittingoscillation of the'vehicle axle relative to the chassis as occurs whereone end of the axle moves up or down relative to its other end.

9. The vehicle suspension assembly of claim 8 wherein only one of theresilient bushing means permits said oscillation. 10. The vehiclesuspension assembly of claim 9 wherein the one bushing means ispermitted limited rotation about the longitudinal axis of the secondbeam to accommodate for axle oscillation.

11. The vehicle suspension assembly of claim 10 wherein the one bushingis at the rearward end of the second beam.

12. The vehicle suspension assembly of claim 5 including meansassociated with at least one of the resilient bushing means for aligningthe axle.

13. A vehicle suspension assembly for supporting a vehicle chassis on avehicle axle comprising an axle mounting bracket to which thevehicle'axle is secured, spring means for resiliently supporting thechassis on the axle, a torque beam, means associated with the chassisfor pivotally supporting the forward end of the torque beam from thevehicle chassis, means associated with the axle mounting bracket forpivotally supporting the rearward end of the torque beam from the axlemounting bracket, and bearing means mounted to the axle bracket forwardof the rearward pivotally supporting means and above the torque beam forbearing downwardly on the torque beam to prevent rotation of the vehicleaxle when the vehicle brakes are applied.

14. The suspension assembly of claim 13 wherein the axle is mounted overthe torque beam.

15. A retractable vehicle suspension assembly for mounting a vehiclechassis to a vehicle axle comprising a first beam, a first air springmeans supported between the forward end of the first beam and thevehicle chassis, the first air spring means being supported such thatpressurization thereof produces downward and rearward movement of theforward end of the first beam, second air spring means supported betweenthe rearward end of the first beam and the vehicle chassis, a secondbeam, means associated with the chassis for pivotally supporting theforward end of the second beam from the vehicle chassis, meansassociated with the first beam for pivotally supporting the rearward endof the second beam from the first beam, and means for mounting thevehicle axle to the first beam, the second beam being supported betweenthe chassis and first beam and the axle mounting position on the firstbeam being such that pressurization of the first air spring means anddepressurization of the second air spring means creates a moment aboutthe pivotally supporting means at the forward raises the axle.

16. The retractable suspension assembly of claim 15 wherein the secondbeam extends downwardly and rearwardly from the chassis to the firstbeam, and the axle is mounted toward the rear of the first beam.

17. A vehicle suspension assembly comprising a first beam, first springmeans between the forward'end of the first beam and thevehicle chassis,second spring means between the rearward end of the first beam andthevehicle chassis, a second'beam, means associated with the chassis forpivotally supporting the forward end of the second beam from the vehiclechassis, means associated with the first beam for pivotally supportingthe rearward end of the second beam from the first beam near therearward end of the first beam, and means for mounting the vehicle axleto the first beam forward of the rearward pivotal supporting means ofthe second beam.

18. A vehicle suspension assembly comprising a first beam, first springmeans between the forward end of the first beam and the vehicle chassis,second spring means between the rearward end of the first beam and thevehicle chassis, a secondbeam, means associated with the chassis forpivotally supporting the forward end of the second beam from the vehiclechassis, means associated with the first beam for pivotally supportingthe rearward end of the second beam from the first beam, means formounting the vehicle axle to the first beam, and means associated withaxle movement and which bears downwardly on the second beam to preventrotation of the axle when the brakes are applied.

19. A vehicle suspension assembly comprising a first beam, first springmeans between the forward end of the first beam and the vehicle chassis,second spring means between the rearward end of the first beam and.

end of the second beam'that or down relative to its other end, and meansfor mounting the vehicle axle to the first beam.

20. The retractable vehicle suspension assembly of claim 16 wherein therearward end of the second beam is pivotally supported near the rearwardend of the first beam, and the vehicle axle is mounted forward of thispivotally supporting means.

1. A vehicle suspension assembly comprising a first beam, first springmeans between the forward end of the first beam and the vehicle chassis,the first spring means being mounted at an inclined angle such thatextension thereof tends to move the forward end of the first beam in adownward and rearward direction, second spring means between therearward end of the first beam and the vehicle chassis, a second beam,means associated with the chassis for pivotally supporting the forwardend of the second beam from the vehicle chassis, means associated withthe first beam for pivotally supporting the rearward end of the secondbeam from the first beam, and means for mounting the vehicle axle to thefirst beam.
 2. The suspension assembly of claim 1 wherein the rearwardend of the second beam is pivotally supported near the rearward end ofthe first beam, and the vehicle axle is mounted forward of thispivotally supporting means.
 3. The suspension assembly of claim 1wherein the first and second spring means are air springs.
 4. Thesuspension assembly of claim 3 including a hanger assembly dependingfrom the vehicle chassis, and means for pivotally mounting the forwardend of the second beam to the hanger assembly.
 5. The suspensionassembly of claim 1 wherein the pivotally supporting means includebushing assemblies having resilient bushing means therein.
 6. Thesuspension assembly of claim 1 including oscillation dampening meansmounted between the first beam and the vehicle chassis.
 7. The vehiclesuspension assembly of claim 1 including a stop means associated withaxle movement and which bears downwardly on the second beam to preventrotation of the axle when the brakes are applied.
 8. The vehiclesuspension assembly of claim 1 wherein the pivotally supporting meansincludes resilient bushing means at least one of which permittingoscillation of the vehicle axle relative to the chassis as occurs whereone end of the axle moves up or down relative to its other end.
 9. Thevehicle suspension assembly of claim 8 wherein only one of the resilieNtbushing means permits said oscillation.
 10. The vehicle suspensionassembly of claim 9 wherein the one bushing means is permitted limitedrotation about the longitudinal axis of the second beam to accommodatefor axle oscillation.
 11. The vehicle suspension assembly of claim 10wherein the one bushing is at the rearward end of the second beam. 12.The vehicle suspension assembly of claim 5 including means associatedwith at least one of the resilient bushing means for aligning the axle.13. A vehicle suspension assembly for supporting a vehicle chassis on avehicle axle comprising an axle mounting bracket to which the vehicleaxle is secured, spring means for resiliently supporting the chassis onthe axle, a torque beam, means associated with the chassis for pivotallysupporting the forward end of the torque beam from the vehicle chassis,means associated with the axle mounting bracket for pivotally supportingthe rearward end of the torque beam from the axle mounting bracket, andbearing means mounted to the axle bracket forward of the rearwardpivotally supporting means and above the torque beam for bearingdownwardly on the torque beam to prevent rotation of the vehicle axlewhen the vehicle brakes are applied.
 14. The suspension assembly ofclaim 13 wherein the axle is mounted over the torque beam.
 15. Aretractable vehicle suspension assembly for mounting a vehicle chassisto a vehicle axle comprising a first beam, a first air spring meanssupported between the forward end of the first beam and the vehiclechassis, the first air spring means being supported such thatpressurization thereof produces downward and rearward movement of theforward end of the first beam, second air spring means supported betweenthe rearward end of the first beam and the vehicle chassis, a secondbeam, means associated with the chassis for pivotally supporting theforward end of the second beam from the vehicle chassis, meansassociated with the first beam for pivotally supporting the rearward endof the second beam from the first beam, and means for mounting thevehicle axle to the first beam, the second beam being supported betweenthe chassis and first beam and the axle mounting position on the firstbeam being such that pressurization of the first air spring means anddepressurization of the second air spring means creates a moment aboutthe pivotally supporting means at the forward end of the second beamthat raises the axle.
 16. The retractable suspension assembly of claim15 wherein the second beam extends downwardly and rearwardly from thechassis to the first beam, and the axle is mounted toward the rear ofthe first beam.
 17. A vehicle suspension assembly comprising a firstbeam, first spring means between the forward end of the first beam andthe vehicle chassis, second spring means between the rearward end of thefirst beam and the vehicle chassis, a second beam, means associated withthe chassis for pivotally supporting the forward end of the second beamfrom the vehicle chassis, means associated with the first beam forpivotally supporting the rearward end of the second beam from the firstbeam near the rearward end of the first beam, and means for mounting thevehicle axle to the first beam forward of the rearward pivotalsupporting means of the second beam.
 18. A vehicle suspension assemblycomprising a first beam, first spring means between the forward end ofthe first beam and the vehicle chassis, second spring means between therearward end of the first beam and the vehicle chassis, a second beam,means associated with the chassis for pivotally supporting the forwardend of the second beam from the vehicle chassis, means associated withthe first beam for pivotally supporting the rearward end of the secondbeam from the first beam, means for mounting the vehicle axle to thefirst beam, and means associated with axle movement and which bearsdownwardly on the second beam to prevent rotation of the axle when thebrakes are applied.
 19. A vehicle susPension assembly comprising a firstbeam, first spring means between the forward end of the first beam andthe vehicle chassis, second spring means between the rearward end of thefirst beam and the vehicle chassis, a second beam, a first resilientbushing means associated with the chassis for pivotally supporting theforward end of the second beam from the vehicle chassis, a secondresilient bushing means associated with the first beam for pivotallysupporting the rearward end of the second beam from the first beam, atleast one of the resilient bushing means permitting oscillation of thevehicle axle relative to the chassis as occurs where one end of the axlemoves up or down relative to its other end, and means for mounting thevehicle axle to the first beam.
 20. The retractable vehicle suspensionassembly of claim 16 wherein the rearward end of the second beam ispivotally supported near the rearward end of the first beam, and thevehicle axle is mounted forward of this pivotally supporting means.